Variable-speed mechanism



April 12 1927.

VARIABLE SPEED MECHANISNIV Filed Maron 19, -1926 5 sheets-sheet 1 12 192 Apr 7 E. c. .HATCHER VARIABLE SPEED MEcHANsM fFi'led March 19, 192e Fig April i2 1927.Y 1,624,835

E. C. HTCHER VARIABLE SPEED MEHANIsE 3 Sheets-@Sheet 5 Filed March 19. 1926 [Il Y E IQ Patented Apr. 12, 1927*.

UNITED STATES PATENT foi-r ICE.

Y ERNEST CHARLES HATCHER, or FiNoHiinY, LONDON, ENGLAND..

'VARIABLE-SPEED MECI-INIFSM. v

Application filed March 19, 1926, Serial No. 96,023, and in Great Britain March 16, r1925.

This invention relatesto Variable speed mechanisms of the type known as infinitely variable, that is to say mechanisms in which, between limits, the speed ratio can be varied by infinitesimal gradations., `The invention relates particularly to mechanisms of the type in whichvariablc rotary motion is obtained by the action of anoscillator of variable amplitude operating through a unidirectional clutch and 2o-operating with a cam like member of variable eccentricity.

The object ofthe invention is to enable a mechanism as aforesaid to be used in a Speed reduction mechanism. It has been proposed previously to employ an oscillator in unidirectional clutch connection with the planet pinion of an epicyclic mechanism, the

`oscillator being controlled by `a cam of variable eccentricity. Such a mechanism can only vbe, used for actuating a driven shaft at the same speed as t-he driving shaft yor at a higher speed.

The present invention comprises the combination with the rollers, pawls or other intermediate connecting devices of a unidirectional clutch, of means for engaging said devices and holding them out of action during alternate phases of motion.

Referring to the three accompanying sheets of'explanatory drawings s Figure l isa longitudinal section,` and Figure 2 a transverse section of a variable speed mechanism constructed in accordance with this invention.

Figures 3 and 4 are part sectional diagrammatic'end and side views, respectively, of a modification of the invention. Figure 5 is a detail perspective of the cam removed.

Referring to Figuresl and 2, a pair of shafts a, Z2, (driver and driven) are mountedcoaxially. On one (a) is secured a planet l carrier c, and on the other (b) a sun 'pinion d. Theplanet carrier has freely mounted' on it at suitable distances apart av plurality of planet wheels e. Coaxially with each planet wheel is arranged an oscillator f in the form 0f one element of a free-wheel clutch. Rollers g in inclined cavities in the outer periphery of each oscillator serve to effect unidirectional driving connection with the inner periphery of the wheel. From one side of the oscillator (and at distance from its cent-re)` extends approjection 7L (preferably carrying a roller i) which co-operates with a circular groove j in one face of a nonrotatable ring 7c which can be moved transversely to the axis ofthe shafts for the purpose of varying the eccentricit-y of the ring, that is to say the axis 0f the ring in relation to the axis ofshafts. The ring can slide on a pair of parallel' guides Z, and is `movable thereon by a screw m operated by a hand wheel n; v

l lVhen the ring is concentric nov relative motion can occur between the sun and planet pinions, and the mechanism rotatesas yone piece. By sliding vthe ring to a new position and thereby imparting to it eccent-ricity, l

increase of speed ofthe driven shaft. The l amount ofy increase depends (in a given.

mechanism) on the eccentricity of the aforesaid ring, the upperlimitbeingdeterminedy by the design of the mechanism.

As already stated, the object of the present l Vinvention is`to enable a mechanism of the kind above described to` rotate the driven shaft at a lower speed than that .of the driver. To enable this result to be Vaccomplished lin accordance with my invention I employ means for holding the rollers gout of action during alternate phases of motion. As shown in Figure 1, for example, such means comprise a fixed cam `ring 0 shown in detail in Figure 5 (the operative surface of which is shown in Figure 1 bydotted lines and the inoperative surfaceV by full lines), and in conjunction with each planet is arranged a pushfrod p, cross pin Q, thrust plate r, push pieces s, a movable plate t and a the rollers g. When by the interaction of vthe ring o and push rod p, the plate t is pressed towards the rollers the ohamfered lips press the rollers backwards slightly rela tively to the part f and -hold them clear of the inner periphery'of the wheel e and so `ring o the rollers are released.

prevent the rollers from acting. After the part 10 has passed the high part ot the cam Y y llVith this arrangement an opposite eit'ec-t to that first described is obtained and the shaft b is driven at a lower rate than the 'shaft ai.v

`Instead of plain toothed pinions, worin gearing may be employed For example, in'V the inner element f of a unidirectional clutch, and intermediate rollers g. A; lever liker extension 7L 'from the element engages an adjustable eccentric 7c. The rollers g can be put ontV 'of action by the plate u which can be moved axially by a lever p cooperating with a cani o. The lever y) engages a screw threaded portion ot the spindle zo Vcarrying the Worm.

The invention is not limited to the particular' iform of unidirectional olii-tch described; for example, pawls may be used insteadot rollers. Also any convenient means acting on the rollers, pawls or the like may be employed for alternately preventing and permitting transmission oit motion itroin one part oi the clutch to the other.

Having thus described my invention what l, claim as new and desire to secure by liet ters Patent is l l. In a variable speed mechanism, drive and driven members, a carrier on one oit' said members, a unidirectional clutch including driving and driven parts carried by the car- Vrier and Vntermediate elements connecting the driving and driven parts, a driving con Lee/rees nection between the driven part` and the other member, means for oscillating the driving part, and means for retaining saidv elementsin inactive position during certain periods. 2. In a variable speed mechanism, drive and driven members, a carrier Von one ot said members, a unidirectional clutch including driving and driven partsl carried by the carrier andV intermediate 'connect-ing elements connecting theV driving and driven parts, a driving-connection between the driven part and the other member, means for oscillating the di.' .'ng part, and cani means for retaining 'said intermediate elements` in inactive position during cer in periods.

.ln a variable speed mechanism,,drive vand driven ii'ienibers, a carrier on one oit said members, aunidircctional clutch including )driving and driven parts carried by' the carrier and intermediate Aconnect-ing elements` connecting the driving and driven parts, a driving connection between the driven part and the other member, means Vfor oscillatingV the driving part, a n'iovabie plate tor displacing the Yinterinediate elements to inactive position, and means l'i'ior controlling said plate. i y i Il. In a; variztble'speed mechanism, drive and driven members, a carrier on one of said inen'ibers, a unidirectional clutch'including driving and driven parts carried by the carrier and intermediate connecting elements connecting the driving and driven parts, a driving connection between the driven part and the other member, means tor oscillating the driving part, a. movable plate for displacing the intermediate elements to inactive position, and means constituted in part by' a cani tor controlling said plate.

In testimonv whereof I have signed my name to this specification.

E. o.. i-nifronnii.v

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